In a continuing effort to improve the quality of shipping fruits, we, the inventors, typically hybridize a large number of peach, nectarine, plum, apricot, and cherry seedlings each year. We also grow a lesser number of open pollinated seeds of each of these fruits. The present invention relates to a new and distinct variety of plum tree which has been denominated varietally as ‘Plumsweet XVIII’.
During a typical blooming season we isolate as seed parents both individual and groups of different plum trees by covering them with screen houses. A hive of bees is placed inside each such house, and bouquets to provide pollen from different plum, apricot, and interspecific plum-apricot hybrid trees are placed in buckets near the trees approximately every two days for the duration of the bloom. During 2003 one such house containing an unpatented purple plum, code named ‘42P1156’, was crossed by us in this manner. To pollinate this purple plum, we selected bouquets from several plum trees without keeping specific written details. Upon reaching maturity the fruit from this plum tree was harvested, and the seeds were removed, cracked, stratified and germinated as a group with the label “H12”. They were grown as seedlings on their own root in our greenhouse and upon reaching dormancy transplanted to a cultivated area of our experimental orchard located near Le Grand, Calif. in Merced County (San Joaquin Valley). During the summer of 2007 the claimed variety was selected by us as a single plant from the group of seedlings described above. Subsequent to origination of the present variety of plum tree, we asexually reproduced it by budding and grafting in the experimental orchard described above, and such reproduction of plant and fruit characteristics were true to the original tree in all respects. The reproduction of the variety included the use of ‘Nemaguard’ (unpatented) rootstock upon which the present variety was true to type.
The present variety is similar to its seed parent, ‘42P1156’ (unpatented) plum tree, by being self-unfruitful and producing fruit that is firm, that is juicy, and that matures in the mid season, but is quite distinguished therefrom by producing fruit that is yellow with dark red dappling instead of solid red to purple in skin color, red instead of yellow in flesh color, sweeter, and oblong to heart shaped instead of globose.
The present variety is most similar to ‘Plumsweet XIV’ (U.S. Plant Pat. No. 23,686) interspecific tree by blooming in the mid season, by being self-unfruitful, and by producing fruit that is clingstone in type, that is sweet, that is firm, that is juicy, that is very good in flavor, and that ripens in the mid season, but is distinguished therefrom by having a larger tree and by producing fruit that is oblong to heart shaped instead of globose, that has much stronger red dappling on the skin, and that is much larger in size.